Ceramic acetabular shell liner with a metal ring having a lead-in surface

ABSTRACT

An acetabular prosthesis for use in a hip arthroplasty surgical procedure is disclosed. The acetabular prosthesis includes an acetabular liner assembly to be secured to an acetabular shell component. The acetabular liner assembly includes a ceramic acetabular shell liner component. The acetabular liner assembly also includes a metal ring affixed to and encircling the ceramic acetabular shell liner component. The metal ring includes a proximal rim shaped to define a lead-in surface.

TECHNICAL FIELD

The present disclosure relates generally to orthopaedic prostheticcomponents and, more particularly, to acetabular prosthetic components.

BACKGROUND

Joint arthroplasty is a surgical procedure in which a patient's naturaljoint is replaced by a prosthetic joint. In a hip arthroplastyprocedure, at least a portion of a patient's hip ball and socket jointis replaced with one or more corresponding prosthetic components. Forexample, the socket portion of the joint, known as the acetabulum, maybe replaced with one or more acetabular prosthetic components (e.g., anacetabular shell that fits within the acetabulum and a liner that fitswithin the shell to act as a bearing surface). Similarly, the ballportion of the joint, known as the femoral head, may be replaced with afemoral head prosthetic component. While many acetabular shell linersare semi-hemispherical in shape (e.g., generally shaped as a hemispherebut not necessarily defining a perfect hemisphere), some patients mayobtain enhanced results when the geometry of the liner is augmented tobe over-hemispherical (e.g., defining more than a hemisphere).

SUMMARY

In one aspect, the present disclosure includes an acetabular prosthesisfor use in a hip arthroplasty surgical procedure. The acetabularprosthesis includes an acetabular liner assembly to be secured to anacetabular shell component. The acetabular liner assembly includes aceramic acetabular shell liner component. The acetabular liner assemblyalso includes a metal ring affixed to and encircling the ceramicacetabular shell liner component. The metal ring includes a proximal rimshaped to define a lead-in surface.

In some embodiments, the metal ring includes titanium. The ceramicacetabular shell liner component may include an outer wall and the metalring may encase a portion of the outer wall less than the entirety ofthe outer wall. The metal ring may be annular in shape and may include adistal rim that has a first diameter that is greater than a seconddiameter of the proximal rim. In some embodiments, the metal ring may bepress fitted onto the ceramic acetabular shell liner component. Theproximal edge of the lead-in surface may be rounded. In someembodiments, the metal ring includes a distal rim that is substantiallycoplanar with a rim of the ceramic acetabular shell liner component. Theouter wall of ceramic acetabular shell liner component may be convexand, in some embodiments, the metal ring may encase the entire convexouter wall of the ceramic acetabular shell liner component.

In another aspect, the present disclosure includes a modular acetabularprosthesis. The modular acetabular prosthesis includes an acetabularshell component shaped to fit in a surgically prepared acetabulum of apatient. The modular acetabular prosthesis also includes an acetabularshell liner assembly that includes a ceramic acetabular shell linercomponent and a metal ring affixed to the ceramic acetabular shell linercomponent. The metal ring encircles an outer wall of the ceramicacetabular shell liner component.

In some embodiments, the metal ring includes titanium. The metal ringmay encase a portion of the outer wall of the ceramic acetabular shellliner, less than the entirety of the outer wall. In some embodiments,the metal ring includes a distal rim having a first diameter and aproximal rim having a second diameter that is less than the firstdiameter. The metal ring may be press fitted onto the ceramic acetabularshell liner component and may have a proximal rim having a lead-insurface that may be rounded. The metal ring, in some embodiments,includes a distal rim that is substantially coplanar with a rim of theceramic acetabular shell liner. In some embodiments, the metal ringencases the entire outer wall of the ceramic acetabular shell liner.

In another aspect, the present disclosure includes a method for using amodular acetabular prosthesis in a hip arthroplasty surgical procedure.The method may include inserting an acetabular shell component into asurgically prepared acetabulum of a patient. The method may also includeinserting, into the acetabular shell component, an acetabular shellliner assembly that includes a ceramic acetabular shell liner componenthaving a metal ring affixed to an outer wall of the acetabular shellliner component. The metal ring is shaped to define a lead-in proximalsurface that aligns the acetabular shell liner assembly with theacetabular shell as the acetabular shell liner assembly is inserted intothe acetabular shell. The method may also include securing a femoralhead component into the acetabular shell liner component after theacetabular shell liner assembly has been inserted into the acetabularshell component.

BRIEF DESCRIPTION OF THE DRAWINGS

The concepts described herein are illustrated by way of example and notby way of limitation in the accompanying figures. For simplicity andclarity of illustration, elements illustrated in the figures are notnecessarily drawn to scale. Where considered appropriate, referencelabels have been repeated among the figures to indicate corresponding oranalogous elements. The detailed description particularly refers to theaccompanying figures in which:

FIG. 1 is an exploded perspective view of an embodiment of a modularacetabular prosthesis having a ceramic acetabular shell liner, a metalring that affixes to the ceramic acetabular shell liner and provides anaugment, and an acetabular shell to receive the ceramic liner and metalring;

FIG. 2 is a perspective view of the ceramic acetabular shell liner ofFIG. 1 ;

FIG. 3 is a perspective view of the ceramic acetabular shell liner ofFIG. 1 , with the metal ring affixed to the liner and a set of keysextending from the metal ring to support an augment;

FIG. 4 is a perspective view of the ceramic acetabular shell liner ofFIG. 1 , with the metal ring affixed to the liner, and the augmentmolded over the set of keys;

FIG. 5 is an exploded perspective view of an alternative embodiment of amodular acetabular prosthesis having a ceramic acetabular shell liner,an augment having a set of tabs that secure the augment to the liner,and an acetabular shell;

FIG. 6 is a perspective view of the modular acetabular prosthesis ofFIG. 5 in which the acetabular shell liner, the augment, and acetabularshell are secured together;

FIG. 7 is a cross-sectional elevation view of the modular acetabularprosthesis of FIG. 5 , taken along line 7-7 of FIG. 6 .

FIG. 8 is an exploded perspective view of an alternative embodiment of amodular acetabular prosthesis having a hybrid augmented acetabular shellliner with a ceramic inner bearing layer, a metal outer support layer,and an integrated augment, and an acetabular shell;

FIG. 9 is a perspective view of the modular acetabular prosthesis ofFIG. 8 in which the hybrid augmented acetabular shell is secured in theacetabular shell;

FIG. 10 is a cross-sectional elevation view of the modular acetabularprosthesis of FIG. 8 taken along line 10-10 of FIG. 9 ;

FIG. 11 is an exploded perspective view of another embodiment of amodular acetabular prosthesis having a ceramic acetabular shell liner,an acetabular shell, and a metal ring that aligns the acetabular shellliner with the acetabular shell during assembly;

FIG. 12 is a perspective view of the ceramic acetabular shell liner ofFIG. 11 with the metal ring affixed thereto;

FIG. 13 is an elevation view of the ceramic acetabular shell liner ofFIG. 11 with the metal ring affixed thereto;

FIG. 14 is a perspective view of a patient's acetabulum with anacetabular shell being advanced towards the acetabulum;

FIG. 15 is a perspective view of the patient's acetabulum with theacetabular shell inserted into the acetabulum and an acetabular shellliner being advanced towards the acetabular shell;

FIG. 16 is a perspective view of the patient's acetabulum with theacetabular shell and liner inserted and a femoral prosthesis componentbeing advanced towards a cavity in the liner; and

FIG. 17 is a perspective view of the femoral prosthesis fitted into theliner.

DETAILED DESCRIPTION OF THE DRAWINGS

While the concepts of the present disclosure are susceptible to variousmodifications and alternative forms, specific embodiments thereof havebeen shown by way of example in the drawings and will be describedherein in detail. It should be understood, however, that there is nointent to limit the concepts of the present disclosure to the particularforms disclosed, but on the contrary, the intention is to cover allmodifications, equivalents, and alternatives consistent with the presentdisclosure and the appended claims.

Terms representing anatomical references, such as anterior, posterior,medial, lateral, superior, inferior, etcetera, may be used throughoutthe specification in reference to the orthopaedic implants or prosthesesand surgical instruments described herein as well as in reference to thepatient's natural anatomy. Such terms have well-understood meanings inboth the study of anatomy and the field of orthopaedics. Use of suchanatomical reference terms in the written description and claims isintended to be consistent with their well-understood meanings unlessnoted otherwise.

Referring now to FIG. 1 , an illustrative modular acetabular prosthesis100 includes an acetabular shell liner assembly 110 and an acetabularshell component 170 (also referred to herein as an acetabular shell). Inuse (e.g., during a hip arthroplasty procedure), the acetabular shellliner assembly 110 is configured to be received into the acetabularshell component 170. In the illustrative embodiment, the acetabularshell liner assembly 110 includes a ceramic acetabular shell linercomponent 120 (also referred to herein as an acetabular shell liner) anda metal ring 140 configured to affix to and encircle the ceramicacetabular shell liner component 120. As discussed in more detailherein, the ring 140 supports (e.g., provides a foundation for, providesreinforcement to, is affixed to, etc.) an augment 150 that, when thering 140 is affixed to the ceramic acetabular shell liner 120, augmentsthe geometry of the ceramic acetabular shell liner 120. That is, theceramic acetabular shell liner 120 is generally semi-hemispherical inshape (e.g., generally hemispherical in shape but not necessarilydefining a perfect hemisphere). However, when the ceramic acetabularshell liner 120 is combined with the augment 150, which extends in adistal direction away from a rim 122 of the acetabular shell liner 120,the resulting geometry of the acetabular shell liner assembly 110 isgenerally over-hemispherical in shape (e.g., defining more than half ofa sphere). The augmented geometry may provide enhanced results for somepatients, such as improving joint stability through a greater range offlexion than other geometries. Furthermore, by supporting the augment150 on the metal ring 140, the ceramic acetabular shell liner 120 may bemanufactured in a single standardized shape while metal rings 140 havingdifferent augments 150 (e.g., of differing geometries and/or materials)may be separately manufactured and affixed to the standardized ceramicacetabular shell liner 120 during an assembly process to obtain avariety of different acetabular shell liner assemblies 110 havingdifferent properties (e.g., geometries, materials, etc.).

In the illustrative embodiment, the ceramic acetabular shell liner 120includes a rim 122 having an inner edge 132 and an outer edge 134. Agenerally hemi-spherical concave inner wall 124 extends inwardly fromthe rim 122 (e.g., from the inner edge 132) in a proximal direction todefine a cavity 128. The cavity 128 is sized and shaped to receive afemoral head (e.g., a femoral head component of a prosthesis or anatural femoral head). As such, the inner wall 124, in operation, actsas a bearing surface for a femoral head. Opposite the inner wall 124,the ceramic acetabular shell liner 120 includes a generallysemi-hemispherical convex outer wall 126. The outer wall 126 includes achannel 130, which may be embodied as a recessed portion that extendsaround a perimeter of the outer wall 126. The channel 130 is sized andshaped to securely engage with the metal ring 140, which, duringassembly, is slid into or otherwise positioned within the channel 130.

In the illustrative embodiment, the metal ring 140 is annular in shape(e.g., to encircle the outer wall 126 of the ceramic liner 120), andincludes a distal rim 142, a proximal rim 148, an inner wall 144 thatextends between the distal rim 142 and the proximal rim 148 along aninner perimeter of the ring 140, and an outer wall 146 that extendsbetween the distal rim 142 and the proximal rim 148 along an outerperimeter of the ring 140. The metal of the ring 140 in the illustrativeembodiment includes titanium. However, in other embodiments, the metalmay include additional or alternative metals (e.g., steel). In someembodiments, the metal ring 140 may be coated with a polymeric material(e.g., polyetheretherketone (PEEK), carbon-fiber-reinforcedpolyetheretherketone (CFR PEEK), low frictionultra-high-molecular-weight polyethylene (UHMWPE), etc.), to provideenhancements to the prosthesis 100 (e.g., inhibiting corrosion, reducinga potential for damage to the femoral head during an instability event,etc.). The augment 150, which may be molded onto the metal ring 140 asdescribed in more detail herein, is illustratively made of a polymericmaterial such as UHMWPE.

The acetabular shell component 170 is somewhat similar in shape to theceramic liner 120, in that the acetabular shell component 170 isgenerally semi-hemispherical. In the illustrative embodiment, theacetabular shell component 170 includes a rim 172, a concave inner wall174 that extends inwardly from the rim 172 in a proximal direction todefine a cavity 178 (e.g., to receive the acetabular shell linerassembly 110), and a convex outer wall 176 that extends from the rim 172in the proximal direction, opposite the inner wall 174. In theillustrative embodiment, the acetabular shell component 170 is made of ametal (e.g., steel). Further, the outer wall 176 of the acetabular shellcomponent 170 has a porous surface to enhance the engagement of theacetabular shell component 170 to an inner surface of a patient'ssurgically prepared acetabulum (e.g., by promoting bone growth intoporous surface). In some embodiments, the porous surface may be a porouscoating, such Porocoat® Porous Coating which is commercially availablefrom DePuy Synthes Products, Inc. of Warsaw, Ind.

Referring now to FIG. 2 , in one stage of a manufacturing process, theceramic acetabular shell liner 120 is produced. As discussed above, inthe illustrative embodiment, the ceramic acetabular shell liner 120includes the channel 130 to accommodate and securely engage with themetal ring 140. The channel 130 extends between a distal edge 160 and aproximal edge 162 around the outer wall 126 of the ceramic acetabularshell liner 120. In the illustrative embodiment, the recess that definesthe channel 130 in the outer wall 126 does not affect the shape of theinner wall 124, which is generally semi-hemispherical and smooth toprovide a continuous bearing surface for a femoral head.

Referring now to FIG. 3 , in a subsequent stage of the manufacturingprocess, the metal ring 140 is press fit into the channel 130, such thatthe distal edge 160 and proximal edge 162 of the channel 130 resistmovement of the ring 140 in a distal or proximal direction. Furthermore,in the illustrative embodiment, the fit between the ring 140 and theouter wall 126 of the liner 120 is sufficiently tight to resist othermovement (e.g., rotation) of the ring 140 relative to the liner 120. Insome embodiments, to reduce the possibility of the ring 140 slidingdistally past the channel 130, the ring 140 and the channel 130 may havea tapered geometry in which the proximal rim 148 of the ring 140 issmaller in diameter than the distal rim 142 of the ring 140 and,likewise, the proximal edge 162 of the channel 130 is smaller indiameter than the distal edge 160 of the channel 130. As shown, in atleast some embodiments, the ring 140 includes a set of keys 152 orprotrusions, each of which extends generally in a distal direction awayfrom the distal rim 142 of the ring 140 and acts as a foundation,skeleton, or inner support structure onto which the augment 150 may bemolded. The keys 152, in addition to extending distally, may also curveoutwards from the ring 140, as shown in FIG. 3 . In other embodiments,the keys 152 may have a different shape. The material from which keys152 are made may be metal (e.g., the metal used in the ring 140, such astitanium), a polymeric material (e.g., UHMWPE), or other material.

Referring now to FIG. 4 , in a subsequent stage of the manufacturingprocess, the augment 150 is affixed to the ring 140. In the illustrativeembodiment, the augment 150 is molded over the keys 152 shown in FIG. 2. In other embodiments, the augment 150 may be affixed to the ring 140by another method (e.g., through a mechanical connection, such as byinserting the keys 152 into corresponding slots in the augment that areshaped to provide an interference lock with the keys 152). As describedabove, and as will be appreciated from the process shown in FIGS. 3-5 ,different augments having different geometries may be formed on the ring140, without affecting the shape or manufacture of the ceramicacetabular shell liner 120 itself.

Referring now to FIG. 5 , another embodiment of a modular acetabularprosthesis 500 includes an acetabular shell liner assembly 510 and anacetabular shell component 570 (also referred to herein as an acetabularshell). The acetabular shell liner assembly 510 includes a ceramicacetabular shell liner component 520 (also referred to herein as anacetabular shell liner) and an augment 550. The ceramic acetabular shellliner component 520 is generally semi-hemispherical in shape and issimilar to the acetabular shell liner component 120. In the illustrativeembodiment, the ceramic acetabular shell liner component 520 includes arim 522 with an inner edge 530 and an outer edge 532, a concave innerwall 524 that extends inwardly in a proximal direction from the rim 522(e.g., from the inner edge 530 of the rim 522) and a convex outer wall526, opposite the inner wall 524, that extends in the proximal directionfrom the rim 522 (e.g., from the outer edge 532 of the rim 522). Theconcave inner wall 524 defines a cavity 528 shaped to receive a femoralhead, and, as such, the inner wall 524 acts as a bearing surface for thefemoral head.

The augment 550, in some respects, is similar to the augment 150, inthat the augment 550 modifies the geometry of the acetabular shell liner520 such that the combined acetabular shell liner assembly 510 isover-hemispherical in shape (e.g., defines more than a hemisphere butless than a total sphere). As such, like the augment 150, the augment550 may provide enhancements for some patients, such as increased jointstability. However, unlike the augment 150, the augment 550 is notmolded onto or otherwise permanently affixed to a metal ring (e.g., themetal ring 140) that fits around an acetabular shell liner. Rather, theaugment 550, in the illustrative embodiment, is a separatelymanufactured component that “snaps” (e.g., press fits) into engagementwith the ceramic acetabular shell liner 520 and the acetabular shellcomponent 570 using a set of tabs 560 or protrusions that extend in aproximal direction and interface with corresponding components of theacetabular shell liner 520 and acetabular shell component 570, asdescribed in more detail herein.

The acetabular shell component 570 is similar in many respects to theacetabular shell component 170, in that the acetabular shell component570 includes a rim 572, a concave inner wall 574 that extends inwardlyin a proximal direction to define a cavity 578, and a convex outer wall576 that extends in the proximal direction from the rim 572, oppositethe inner wall 574. Like the outer wall 176, the outer wall 576 may havea porous surface (e.g., a porous coating). Further, in the illustrativeembodiment, the rim 572 includes an inner portion 580 and an outerportion 582. As shown, the inner portion 580 extends slightly further ina distal direction than the outer portion 582 of the rim 572. Further,the inner portion 580 of the rim 572 includes slots 590 or recessesspaced around the perimeter of the inner portion 580. The slots 590function to resist rotation of a component (e.g., the augment 550)having corresponding parts (e.g., the tabs 560) that fit into one ormore of the slots 590.

The augment 550, in the illustrative embodiment, is generally curved(e.g., from a plan view) and shaped to fit over a portion (e.g., lessthan the entire perimeter) of the rim 522 of the ceramic acetabularshell liner 520 and a corresponding portion of the rim 572 of theacetabular shell component 570. Illustratively, the augment 550 includesa rim 552 from which an inner wall 554 extends in a proximal directionand an outer wall 556, opposite the inner wall 554, extends in theproximal direction. The augment 550 defines a channel 558 or recess thatextends along a curved path between the outer wall 556 and the tabs 560.The channel 558 is sized and shaped to straddle (e.g., fit around) theinner portion 580 of the rim 572 of the acetabular shell 570 (e.g., toresist lateral movement of the augment 550 relative to the acetabularshell 570). To further resist undesired movement of the augment 550, thetabs 560 are sized and shaped to fit within corresponding slots 590 orrecesses in the rim 572 of the acetabular shell 570 and to be locked inplace (e.g., by an interference lock formed by a taper interface betweeneach tab 560 and the outer edge 532 of the rim 522 of the ceramic liner520). The fit of the tabs 560 is described in greater detail withreference to FIG. 7 below.

Referring now to FIG. 6 , the modular acetabular prosthesis 500 is shownin its assembled form. As shown, the ceramic acetabular shell liner 520fits within the acetabular shell 570 and the augment 550 fits over therims 522, 572, providing the otherwise generally semi-hemisphericalprosthesis an over-hemispherical geometry (e.g., to improve thestability of the resulting joint). Referring to FIG. 7 , it can be seenthat the rims 522, 572 are substantially coplanar (e.g., defining animaginary plane 710) while the augment 550 defines an imaginary plane720 at a non-orthogonal angle 730 (e.g., 15 degrees) to the imaginaryplane 710. Focusing now on the fit between the augment 550, theacetabular shell liner 520, and the acetabular shell 570, it can be seenthat each tab 560 of the augment 550 is interposed or squeezed betweenthe ceramic liner 520 and the acetabular shell 570 near their rims 522,572 (e.g., between the outer edge 532 of the rim 522 and the innerportion 580 of the rim 572). In the illustrative embodiment, the outeredge 532 is tapered outwards (e.g., increasing in diameter moving from aproximal portion of the outer edge 532 to a distal portion of the outeredge 532) and the tab 560 has a corresponding taper, such that a taperinterface 566 is formed between the tab 560 and the outer edge 532 ofthe rim 522 of the liner 520. Additionally, as can be seen in FIG. 7 ,the channel 558 straddles the inner portion 580 of the rim 572 of theacetabular shell 570. Further, the augment 550 has a flat contactportion 562 that rests upon the rim 522 of the ceramic liner 520 andanother flat contact portion 564 that rests upon the outer portion 582of the rim 572 of the acetabular shell 570. The flat contact portions562, 564 may operate to shield stress on the tabs 560 during flexion ofthe prosthetic joint.

Referring now to FIG. 8 , in another embodiment of a modular acetabularprosthesis 800, a hybrid augmented acetabular shell liner component 820(also referred to herein as a hybrid augment acetabular shell liner) isshaped to fit into a corresponding acetabular shell component 870 (alsoreferred to herein as an acetabular shell). The acetabular shell 870 issimilar to acetabular shell 570 in that the acetabular shell 870includes a rim 872, a concave inner wall 874 extending inwardly in aproximal direction to define a cavity, and a convex outer wall 876extending from the rim 872 in the proximal direction. Referring back tothe hybrid augmented acetabular shell liner 820, unlike the liners 120and 520, the liner 820 is manufactured to have an integrated augment 850(e.g., augment 850 is not a separate piece that is fitted or affixed tothe liner 820). Further, the liner 820 is a hybrid liner in that theliner 820 includes two layers of different material. That is, in theillustrative embodiment, the liner 820 includes an inner bearing layer830, which is concave and made of ceramic, and an outer reinforcementlayer 840, which is convex and made of metal (e.g., titanium). The outerreinforcement layer 840 is generally coextensive with the inner bearinglayer 830, providing a relatively strong backing to the ceramic even insections (e.g., the integrated augment 850) that are not reinforced bythe acetabular shell 870 when the prosthesis 800 is assembled. In someembodiments, the metal of the outer reinforcement layer 840 may becoated with a polymeric material.

As can be seen in FIG. 8 , the liner 820 includes a rim 822 with aninner edge 824 and an outer edge 826 opposite the inner edge 824. Theinner bearing layer 830 extends inwardly in a proximal direction fromthe inner edge 824 of the rim 822 and defines a cavity 828 shaped toreceive a femoral head. The outer reinforcement layer 840 extends in aproximal direction from an outer edge 826 of the rim 822 and is shapedto be received into the acetabular shell 870. The liner 820 has agenerally semi-hemispherical body 890 formed by generallysemi-hemispherical portions of the inner bearing layer 830 and the outerreinforcement layer 840. The augment 850, which extends distally fromthe semi-hemispherical body 890, gives the liner 820 anover-hemispherical shape. As stated above, and as shown in FIG. 8 , theaugment 850 is integral to the acetabular shell liner 820 and, in theillustrative embodiment, the rim 822 is continuous between the body 890and the augment 850. As such, the rim 822 has a proximal portion 832(e.g., a rim of the body 890) and a distal portion 852 (e.g., a rim ofthe augment 850).

Referring now to FIG. 9 , the acetabular prosthesis 800 is shown in itsassembled form. As can be seen, the hybrid liner 820 fits within (e.g.,press fits and locks within) the acetabular shell 870 and the augment850 extends distally therefrom, providing an over-hemispherical shape tothe prosthesis 800. While the acetabular shell 870 providesreinforcement to the body 890 of the liner 820 when the liner 820 issecured therein, the ceramic augment 850, which extends out of theacetabular shell 870, is reinforced by the metal outer reinforcementlayer 840.

Referring now to FIG. 10 it can be seen that an inner wall 892 of themetal outer reinforcement layer 840 is affixed to an outer wall 894 ofthe ceramic inner bearing layer 896 (e.g., during a manufacturingprocess). Further, the over-hemispherical shape of the hybrid acetabularshell liner 820 can be seen. The rim 872 and the proximal portion 832 ofthe rim 822 are generally co-planar, forming an imaginary plane 1010 andthe augment 850 forms an imaginary plane 1020 that is at anon-orthogonal angle 1030 (e.g., 15 degrees) to the imaginary plane1010. The resulting geometry is an over-hemispherical shape (e.g.,defining more than a hemisphere but less than a total sphere) that mayprovide enhanced joint stability for some patients.

Referring now to FIG. 11 , another embodiment of a modular acetabularprosthesis 1100 includes a modular acetabular shell liner assembly 1110and an acetabular shell component 1170 (also referred to herein as anacetabular shell). The acetabular shell component 1170 is similar to theacetabular shells 170, 570, 870 and is generally semi-hemispherical inshape, with a rim 1172, a concave inner wall 1174 that extends inwardlyin a proximal direction to define a cavity (e.g., to receive theacetabular liner assembly 1110), and a convex outer wall 1176 whichextends in the proximal direction from the rim 1172 and is shaped to fitwithin a surgically prepared acetabulum. The acetabular shell, in theillustrative embodiment, is made of metal and, like the acetabularshells 170, 570, 870, may have a porous surface (e.g., a porous coating)on the outer wall 1176 (e.g., to enhance the engagement of theacetabular shell 1170 with an inner surface of the acetabulum).

The acetabular shell liner assembly 1110, in the illustrativeembodiment, includes a ceramic acetabular shell liner component 1120(also referred to herein as the ceramic acetabular shell liner) and ametal ring 1140 that affixes to (e.g., press fits onto) and encirclesthe ceramic acetabular shell liner 1120. The ceramic acetabular shellliner 1120 is generally semi-hemispherical in shape, with a rim 1122having an inner edge 1130 and an outer edge 1132, a concave inner wall1124 that extends inwardly in a proximal direction from the inner edge1130 to defined a cavity 1128 shaped to receive a femoral head, and aconvex outer wall 1126 that extends in the proximal direction oppositethe inner wall 1124 and is shaped to be received into the cavity 1178.

The metal ring 1140, which may be made of titanium or another metal,functions as a shield to absorb impacts when the liner assembly is beingfitted into the acetabular shell component 1170 during a hiparthroplasty procedure. The metal ring 1140 also operates to align theliner assembly 1110 into the acetabular shell component 1170 duringinsertion. That is, in the illustrative embodiment, the metal ring 1140,which is annular in shape and has an inner wall 1144 and an outer wall1146 that both extend between a distal rim 1142 and a proximal rim 1148,has a lead-in surface 1150 at the proximal rim 1148 that is rounded andguides or centers the acetabular shell liner assembly 1110 into thecavity 1178 of the acetabular shell 1170 when a surgeon is fitting theassembly 1110 into the acetabular shell 1170. In some embodiments, themetal ring 1140 may be shaped as a sleeve that encases the entire outerwall 1126 of the ceramic liner 1120.

Referring now to FIG. 12 , a perspective view of the acetabular shellliner assembly 1110 in its assembled form is shown. As can be seen, thedistal rim 1142 of the metal ring 1140 is substantially co-planar withthe rim 1122 of the acetabular shell liner component 1120. The innerwall 1144 of the metal ring 1140 and the outer wall 1126 of theacetabular shell liner 1120 may be tapered to provide a press fitbetween the metal ring 1140 and the liner 1120, such that when the metalring 1140 is slid onto the liner 1120 (e.g., in a distal direction), themetal ring 1140 is unable to slide farther (e.g., in the distaldirection) once the rim 1122 and the distal rim 1142 are substantiallyco-planar. As shown in FIG. 12 , the outer wall 1126 extends beyond theproximal rim 1148, in the proximal direction. However, in someembodiments and as stated above, the metal ring 1140 may encase theentire outer wall 1126 of the liner 1120.

Referring now to FIG. 13 , from the elevation view, it can be seen thatthe lead-in surface 1150 is rounded to smoothly align the assembly 1110into the cavity 1178 (e.g., into engagement with the inner wall 1174) ofthe shell 1170 when the assembly 1110 is inserted into the shell 1170 bya surgeon during a hip arthroplasty surgical procedure. As shown, thelead-in surface 1150 is somewhat conical in shape in that the metal ring1140 has a diameter 1310 that is greater than another diameter 1320closer to the proximal rim 1148 (e.g., the diameter of the metal ring1140 gradually increases as a function of its distance from the proximalrim 1148).

Referring now to FIG. 14 , a method for using a modular acetabularprosthesis (e.g., the prosthesis 100, 500, 800, 1100) in a hiparthroplasty procedure may begin with a surgeon inserting an acetabularshell (e.g., the shell 170, 570, 870, 1170) into a surgically prepared(e.g., by a surgical reamer) acetabulum of a patient. The surgeon maypress fit the acetabular shell into place using a driver tool. In someembodiments, the surgeon may additionally thread one or more screwsthrough one or more bores in the acetabular shell to further secure theshell in the acetabulum. In yet other embodiments, the surgeon mayutilize other techniques, such as use of orthopaedic cement, to securethe shell into the acetabulum.

Referring now to FIG. 15 , the surgeon may subsequently secure, into theacetabular shell (which has been inserted into the acetabulum, asdescribed above), an acetabular shell liner assembly (e.g., theacetabular shell liner assembly 110, 510, 820, 1110). In the case of theacetabular shell liner assembly 1110, the lead-in surface 1150 of themetal ring 1140 aligns the assembly into the acetabular shell andabsorbs any impacts with any portion of the acetabular shell (e.g., theinner wall) that may occur during the process. As described above, theacetabular shell liner may be shaped to lock into the acetabular shell(e.g., due to the tapered outer wall of the acetabular shell liner).Additionally or alternatively, in some embodiments, the acetabular shellliner may be secured into the acetabular shell using another mechanism(e.g., one or more screws).

Referring now to FIGS. 16 and 17 , with the acetabular shell and theacetabular shell liner assembly in the patient's acetabulum, the surgeonmay fit a head of a femoral prosthesis into a cavity defined by theacetabular shell liner. In subsequent steps, the surgeon may test thefit and range of motion of the femoral head in the modular acetabularprosthesis. In some embodiments, the acetabular shell and/or linerassembly may be or include trial components (e.g., instruments) that thesurgeon may swap out with other trial components having the featuresdescribed herein, before determining that a particular combination ofacetabular shell and liner assembly (e.g., which may include an augment)provides a satisfactory fit and range of motion. Afterwards, the surgeonmay replace the trial components (e.g., instruments) with permanentimplant versions of the components.

While certain illustrative embodiments have been described in detail inthe drawings and the foregoing description, such an illustration anddescription is to be considered as exemplary and not restrictive incharacter, it being understood that only illustrative embodiments havebeen shown and described and that all changes and modifications thatcome within the spirit of the disclosure are desired to be protected.

There are a plurality of advantages of the present disclosure arisingfrom the various features of the method, apparatus, and system describedherein. It will be noted that alternative embodiments of the method,apparatus, and system of the present disclosure may not include all ofthe features described yet still benefit from at least some of theadvantages of such features. Those of ordinary skill in the art mayreadily devise their own implementations of the method, apparatus, andsystem that incorporate one or more of the features of the presentinvention and fall within the spirit and scope of the present disclosureas defined by the appended claims.

The invention claimed is:
 1. An acetabular prosthesis for use in a hiparthroplasty surgical procedure, the acetabular prosthesis comprising:an acetabular liner assembly to be secured to an acetabular shellcomponent, the acetabular liner assembly comprising: a ceramicacetabular shell liner component including an outer surface having acurvature; and a metal ring affixed to and encircling the ceramicacetabular shell liner component, wherein the metal ring comprises adistal rim, a proximal rim, and an outer wall that extends from thedistal rim to the proximal rim, wherein the outer wall defines adiameter of the metal ring that increases as a function of a distancefrom the proximal rim, and wherein the proximal rim is shaped to definea lead-in surface that is rounded inwardly toward a longitudinal axis ofthe metal ring, wherein a curvature of the lead-in surface isnon-congruent with the curvature of the outer surface of the ceramicacetabular shell liner component.
 2. The acetabular prosthesis of claim1, wherein the metal ring comprises titanium.
 3. The acetabularprosthesis of claim 1, wherein the ceramic acetabular shell linercomponent comprises an outer wall and the metal ring encases a portionof the outer wall less than the entirety of the outer wall.
 4. Theacetabular prosthesis of claim 1, wherein the metal ring is annular inshape.
 5. The acetabular prosthesis of claim 1, wherein the distal rimof the metal ring has a first diameter greater than a second diameter ofthe proximal rim of the metal ring.
 6. The acetabular prosthesis ofclaim 1, wherein the metal ring is press fitted onto the ceramicacetabular shell liner component.
 7. The acetabular prosthesis of claim1, wherein the distal rim of the metal ring is substantially coplanarwith a rim of the ceramic acetabular shell liner component.
 8. A modularacetabular prosthesis comprising: an acetabular shell component shapedto fit in a surgically prepared acetabulum of a patient; and anacetabular shell liner assembly comprising: a ceramic acetabular shellliner component including an outer surface having a curvature; and ametal ring affixed to the ceramic acetabular shell liner component,wherein the metal ring encircles an outer wall of the ceramic acetabularshell liner component and comprises a distal rim, a proximal rim, and anouter wall that extends from the distal rim to the proximal rim, whereinthe outer wall defines a diameter of the metal ring that increases as afunction of a distance from the proximal rim, and wherein the proximalrim includes a lead-in surface that is rounded inwardly toward alongitudinal axis of the metal ring, wherein a curvature of the lead-insurface is non-congruent with the curvature of the outer surface of theceramic acetabular shell liner component.
 9. The modular acetabularprosthesis of claim 8, wherein the metal ring comprises titanium. 10.The modular acetabular prosthesis of claim 8, wherein the metal ringencases a portion of the outer wall of the ceramic acetabular shellliner less than the entirety of the outer wall.
 11. The modularacetabular prosthesis of claim 8, wherein the distal rim of the metalring has a first diameter and the proximal rim of the metal ring has asecond diameter less than the first diameter.
 12. The modular acetabularprosthesis of claim 8, wherein the metal ring is press fitted onto theceramic acetabular shell liner component.
 13. The modular acetabularprosthesis of claim 8, wherein the distal rim of the metal ringsubstantially coplanar with a rim of the acetabular shell liner.
 14. Amethod for using a modular acetabular prosthesis in a hip arthroplastysurgical procedure, the method comprising: inserting an acetabular shellcomponent into a surgically prepared acetabulum of a patient; andinserting, into the acetabular shell component, an acetabular shellliner assembly that includes a ceramic acetabular shell liner componenthaving a metal ring affixed to an outer wall of the acetabular shellliner component, wherein the metal ring comprises a distal rim, aproximal rim, and an outer wall that extends from the distal rim to theproximal rim, wherein the outer wall defines a diameter of the metalring that increases as a function of a distance from the proximal rim,and wherein the proximal rim is shaped to define a lead-in proximalsurface that (i) is rounded inwardly toward a longitudinal axis of themetal ring and (ii) aligns the acetabular shell liner assembly with theacetabular shell as the acetabular shell liner assembly is inserted intothe acetabular shell, and wherein a curvature of the lead-in proximalsurface is non-congruent with a curvature of the outer surface of theceramic acetabular shell liner component.
 15. The method of claim 14,further comprising securing a femoral head component into the acetabularshell liner component after the acetabular shell liner assembly has beeninserted into the acetabular shell component.